perf ui: Restore SPACE as an alias to PGDN in annotate

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/newt.c

@@ -750,6 +750,7 @@ int hist_entry__tui_annotate(struct hist_entry *self)
 
 	browser.width += 18; /* Percentage */
 	ui_browser__show(&browser, self->ms.sym->name);
+	newtFormAddHotKey(browser.form, ' ');
 	ret = ui_browser__run(&browser, &es);
 	newtFormDestroy(browser.form);
 	newtPopWindow();